THE publication of a translation of Hermann Müller's Die
Befruchtung der Blumen &c.,1 will without doubt be a great
service to every English botanist or entomologist who is interested in
general biological problems. The book contains an enormous mass of
original observations on the fertilisation of flowers, and on the part
which insects play in the work, given with much clearness and
illustrated by many excellent woodcuts. It includes references to
everything which has been written on the subject; and in this respect
the English edition will greatly exceed in value even the original
German edition of 1873, as Müller has completed the references up to
the present time. No one else could have done the latter work so well,
as he has kept a full account of all additions to our knowledge on this
subject. Any young observer who, after reading the whole or part of the
present work, will look, for instance, at the flower of a Salvia, or of
some Papilionaceous or Fumariaceous plant, or at one of our common
Orchids, will be delighted at the perfection of the adaptations by
which insects are forced, unconsciously on their part, to carry pollen
from the stamens of one plant to the stigma of another. Design in
nature has for a long time deeply interested many men, and though the
subject must now be looked at from a somewhat different point of view
to what was formerly the case, it is not thus rendered the less
interesting.

Hermann Müller has by no means confined his attention to the manner
in which pollen is carried by insects or other animals from plant to
plant, for wind-fertilised flowers have been carefully described by
him; and several curious transitions from the one state to the other
are noticed. He has also attended more closely than any one else to the
many contrivances for self-fertilisation, which sometimes co-exist with
adaptations for cross-fertilisation. For instance, he has discovered
the singular fact that with certain species two kinds of plants are
regularly produced, one bearing inconspicuous flowers fitted for
self-fertilisation, and the other kind with much more conspicuous
flowers fitted for cross-fertilisation. The flowers on the
first-mentioned plants serve the same end as the curious little closed
cleistogamic flowers which are borne by a considerable number of
plants, as described and enumerated in the present work.

There is another interesting feature in the Befruchtung,
by which it differs from all other works on the same subject; for it
includes not only an account of the adaptation of flowers to insects,
but of different insects to differently constructed flowers for the
sake of obtaining their nectar and pollen.

Any one who will carefully study the present work and then observe
for himself, will be sure to make some interesting discoveries; and as
the references to all that has been observed are so complete, he will
be saved the disappointment of finding that which he thought was new
was an already well-known fact. I may perhaps be permitted here to
mention a few points which seem to me worthy of further investigation.
There are many inconspicuous flowers which during the day are rarely or
never visited by insects, and the natural inference seems to be that
they must be invariably self-fertilised; for instance, this is the case
with some species of Trifolium and Fumaria which bear very small
flowers, with some species of Galium, Linum catharticum,&c.
Many other such flowers are enumerated by Müller. Now it is highly
desirable that it should be ascertained whether or not these flowers are

visited at night by any of the innumerable individuals of the many
species of minute moths. A lepidopterist while collecting at night, if
endowed with only a small portion of the indomitable patience displayed
by Müller, could ascertain this fact. The question possesses a
considerable degree of theoretical interest; for if these inconspicuous
flowers are never visited by insects, why, it may be asked, do they
expand, and why is not the pollen protected by the petals remaining
closed, as in the case of cleistogamic flowers? It would perhaps be
possible to smear such small flowers with some viscid matter, and an
examination of the petals would probably reveal nocturnal visits by
moths by the presence of their scales; but it would be necessary to
prove that the matter employed was not in itself attractive to insects.
H. Müller gives long lists of the several kinds of insects which he has
seen visiting various flowers in Germany; and it would be interesting
to learn whether the same insects and the same proportional number of
insects belonging to the different orders, visit the same plants in
England as in Germany.

There are many other subjects which it is desirable that some one
should investigate, for instance, by what steps heterostylism (of which
an account will be found in the present work) originated: and with
trimorphic heterostyled plants we meet with a more extraordinary and
complicated arrangement of the reproductive system than can be found in
any other organic beings. In order to investigate this subject and
several others, experiments in fertilisation would have to be tried;
but these are not difficult and would soon be found interesting. For
instance, there are some plants, the pistils and stamens of which vary
much in length, and we may suspect that we here have the first step
towards heterostylism; but to make this out, it would be necessary to
test in many ways the power of the pollen and of the stigma in the
several varieties. There exist also some few plants the flowers of
which include two sets of stamens, differing in the shape of the
anthers and in the colour of the pollen; and at present no one

knows whether this difference has any functional signification, and
this is a point which ought to be determined. Again, there are other
plants, for instance, the common Rhododendron, in which the shorter
stamens are more or less rudimentary, and it has been asserted that
seedlings raised from pollen taken from the short and from the
full-sized stamens differ in appearance; and it would be of importance
to know whether they differ in their fertility or power of yielding
seeds. It would also be interesting to learn whether in the plants,
already alluded to, which produce two forms, one adapted for
self-fertilisation and the other for cross-fertilisation, the
reproductive organs have become in any degree differentiated, so that
their action would not be perfect if the two forms were reciprocally
crossed. Would a flower adapted for self-fertilisation yield a full
complement of seed if fertilised by pollen from one adapted for
cross-fertilisation; and vice-versâwith
the other form?

But it would be superfluous to make any further suggestions. These
will occur in abundance to any young and ardent observer who will study
Müller's work and then observe for himself, giving full play to his
imagination, but rigidly checking it by testing each notion
experimentally. If he will act in this manner, he will, if I may judge
by my own experience, receive so much pleasure from his work, that he
will ever afterwards feel grateful to the author and translator of the Befruchtung
der Blumen.